The appropriate management of limb threatening lower extremity injuries is the subject of extensive debate in the orthopedic and trauma literatures. Although limb salvage is now technically feasible in all but very few cases, it is becoming increasingly apparent that limb salvage does not always equate with good function and patient well-being. Indeed there is evidence to suggest that for some types of injuries and patients, an early amputation results in better outcome than does a long, costly reconstruction. At present, however, the decision to amputate versus reconstruct is most often based on subjective parameters because realistic limits of limb salvage have not been defined nor specific indications for primary amputation been elucidated. The objective of this study is to develop a scientifically sound knowledge base which can be used by clinicians together with patients and families in deciding on an appropriate choice of therapy. The specific aims are: (l) to determine the clinical and functional outcomes (including health-related quality of life) following severe, high energy, lower extremity trauma. (2) To estimate the direct and indirect costs associated with these injuries. (3) To identify early clinical predictors of successful limb salvage and good functional outcomes. (4) To identify characteristics of the acute treatment that explain variations in clinical and functional outcomes and (5) to identify characteristics of the patient and his environment that mediate the quality of functional outcomes and general well-being following amputation versus reconstruction. Of primary interest is a comparison of costs and outcomes for 3 major patient subgroups: (A) early amputation (B) delayed amputation and (C) successful limb salvage. The study will consist of a prospective, longitudinal study of approximately 700 patients aged 18-54, treated at 12 level I trauma centers across the Country. Study patients will be interviewed during the initial hospitalization, at 3 month intervals during the first year post- injury and at 6 month intervals during the second year post. One half of the study population will be interviewed again at 36 months. Patients will also be clinically assessed by an orthopedist and a physical therapist at discharge from the hospital and at 3, 6, 12, 18, 24 and 36 months. These data will be used to address the study's aims and to develop an initial set of guidelines for treating massive lower extremity trauma.